Response continues to mineral oil leak in Straits of Mackinac

Straits of Mackinac during a Coast Guard Air Station Traverse City MH-60 overflight on April 4, 2018. (U.S. Coast Guard photo).

MACKINAW CITY, Mich. – The Unified Command, comprised of the U.S. Coast Guard, the Michigan Department of Environmental Quality, a representative of numerous Michigan tribes, and the responsible party, American Transmission Company, continues to oversee response efforts, Monday.

Work to extract the remaining product from two cables continued through the weekend. ATC, a transmission-only electric utility, contracted North Shore Environmental to remove product from the cables. North Shore Environmental is vacuuming the mineral oil from a shoreside facility a through a less than one-inch-diameter void in the cables that stretch three-and-a-half miles across the Straits of Mackinac.

To date, approximately 250 gallons of mineral oil has been extracted from one of the utility cables. Work to remove product from the second damaged cable will commence when the first one is complete. Each cable can hold up to 400 gallons. Product in each cable was secured Tuesday, April 3, and there is no evidence of any ongoing release. The estimated spill of mineral oil from the leak is 600 gallons.

The mineral oil in the cables acts as an insulator to ensure the integrity of the electricity within the cable.

A Coast Guard marine science technician and an environmental quality analyst for Michigan’s Department of Environmental Quality transited the Straights of Mackinac by boat on Saturday and Sunday and observed no signs of pollution. Another Coast Guard marine science technician was present onboard an overflight on Saturday and Sunday and saw no signs of a sheen.

The United States Department of Agriculture’s Animal and Plant Health Inspection Service, Michigan Department of Environmental Quality, and a Michigan Department of Natural Resources wildlife biologist also surveyed the area on the water and from the shore to look for any signs of pollution or impacted fish and wildlife. No impacts to the environment or wildlife have been identified.

“During the weekend, we surveyed the areas near Mackinac, Round, and Boise Blanc Islands. We then surveyed near the shoreline of Mackinaw City and went west of the bridge,” said Anthony Wilson, wildlife specialist with the USDA Animal and Plant Health Inspection Service (APHIS, Wildlife Services). “We did not see any oil sheen or injured wildlife. We observed more than 1,200 water fowl including long-tailed ducks, common mergansers, herring gulls, common loon and even a bald eagle.”

“Our top priorities remain protecting public health, the safety of the communities in the region and responders, and to limit the environmental impacts from the product that was discharged,” said Coast Guard Capt. Marko Broz, the Federal On-Scene Coordinator for the response. “I am very pleased with the partnership thus far between the federal, state, tribal, and local agencies to ensure the safe extraction of the remaining mineral oil in the two cables and to identify any signs of pollution or negative impact to the environment and wildlife. Moving forward, our focus remains on the effective extraction of the oil from the two cables, protecting wildlife, and identifying any further damage to infrastructure in the Straits.”

The mineral oil leak from ATC’s utility cables remains under investigation. All entities responsible for active utility lines that cross the Straits have been notified by the Unified Command to ensure that all steps are taken to assess and mitigate any further damage to infrastructure or risk to public health and the environment. There have been no further indications of damage or possible pollution. However, the utilities are continuing to conduct assessments of their infrastructure.

The U.S. Coast Guard is designated as the lead federal agency for directing and overseeing removal and cleanup efforts by the responsible party in the coastal zone.

To report affected wildlife, please call the USDA at (517)-336-1928.

To report any oil sheen or pollution, please call the National Response Center at 1-800-424-8802.